Hi Guys/Gals
I have been doing a few checks and calculations and have found that my AUII Fairmont speedo is optimistic by about 3.3% with the standard 215/60/16 tyres but as I am going to fit Tickford 17 inch wheels with 235/45/17 tyres this optimism will be compounded by another 3.3% for a total of 6.7%
I was going to fit a "Yellow Box" electronic recalibrator made by Blackrobotics of Wollongong but their web page appears to have vanished.
Does anyone have an address that I can write to, or a phone number so I can contact them.
Also has anyone else installed one of these units to a late model Ford - if so how successful was the result

Originally posted by IIV8II
Yep; don't have details tonite - will get tomorrow. It's a place in Silverwater and they calibrate cop cars. I'm sure they have a interceptor box jobbie that 'alters' the speedo

You may want to try an easier way and change your speedometer drive gear. There are 3 used on the AUII Falcons.

6 Cyl. Sedan Auto's (non LSD) with a 3.08:1 diff have a brown 20 tooth gear
8 Cyl. and 6 Cyl. Auto with a 3.23:1 diff have a light green 21 tooth gear
XR's, both auto and manual have a 3.45:1 diff and use a grey 22 tooth gear

If you go from 20 to 21 teeth that'll decrease your speedo reading by 5%, from 20 to 22 will decrease it by 10% and from 21 to 22 will decrease it by 4.8%. Not exactly your 6.7% that you wanted but it could help.

How are you checking your speedo accuracy? I find the best way is to use a hand held GPS unit that gives a speed readout.

The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.

AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.